緩急かんきゅう
kankyū

Noun

1. high and low speed; fast and slow; pace; tempo

Noun

2. lenience and severity

Noun

3. emergency; crisis; dire situation

いつもお世話せわになっていますから、一旦いったん緩急かんきゅうあれば、すぐさまさんじます。
itsumo osewani natte imasukara ittan kankyū areba sugusama hasesanjimasu.
You're always there for me, so if you're ever in dire straits, just let me know and I'll come running.